A snapshot of knowledge: Laptop camera technology

CAMERA ENHANCEMENT

Quality Factors for Streaming Video Noise

Temporal Noise (TN) is noise that occurs over time (from frame to frame) in a moving image, versus Spatial Noise (SN) which is signal noise in a single frame. Temporal Noise is inherent in digital sensors due to variations in individual pixel signal levels. TN is caused by movement of sensor electrons (and variations in levels of light photons) captured during a discrete sampling window. Temporal Noise Reduction (TNR) is one of the most critical elements of video quality for video streaming. TNR is implemented on the Image Signal Processors (ISP). It compares pixels on subsequent frames to isolate and eliminate variations identified as noise.

Noise becomes more prominent in low lighting conditions due to the fact that it increases as a percentage of the total signal.

Laptop Camera Technology

Dell business laptops and mobile workstations have been designed to be your modern essential tool of the digital era. These devices are meant to enable getting your work done quickly and efficiently to make you the most productive. On top of that, they are also designed with connectivity and collaboration features which are now a huge component to enable ‘work from anywhere’. In particular, the video conferencing movement is an important aspect of a now common business-day routine. In April of 2020, Zoom was seeing 300 million daily participants (vs. 10 million in December of 2019)*. With this sudden boom in video conferencing, Dell’s built-in “webcams” were becoming more important to customers.

There are also many different factors that can affect streaming video that we will outline in this paper. Resolution (HD, FHD, etc.) is only one aspect of many that can affect image quality – camera size, sensitivity, noise, dynamic range, and color accuracy also play a part in providing best video quality. In Dell’s Latitude laptop portfolio, we strive to lead the industry with innovation such as the industry’s first SafeShutter which is an automatic webcam that knows when to open or close by syncing to your video conferencing applications.¹ This paper will dig into the details on such features as well as provide some useful information about webcam video factors.

Original Image 3dB TN

6dB TN 9dB TN

* IQBAL, MANSOOR. “Zoom Revenue and Usage Statistics (2020).” Business of Apps, Business of Apps, 10 Mar. 2021, www.businessofapps.com/data/zoom-statistics.

To combat this Noise, Dell offers Temporal Noise Reduction (TNR), others since have followed our lead. We even have a larger percentage of our cameras that support the latest versions of TNR, and in many cases, we think our camera tuning is better than most competitors.

CAMERA ENHANCEMENT

Dynamic Range

Dynamic Range refers to the range of brightness from darkest to brightest in a scene. Wide Dynamic Range (WDR) is a technology that extends the camera’s optical sensing range to cover a greater span between the brightest and the darkest areas in the image. Each image frame with Dynamic-Range Optimization improves the video performance due to the high contrast scene, non-uniform lighting conditions, and sensor limitations. Varying lighting conditions within a frame, and over time, must be balanced across the limited dynamic range of a camera sensor.

Color Accuracy

White balance is the process of removing unrealistic color casts, so that white objects appear the right white color in the image/video. Auto White Balance is an adjustment method in the color correction and image processing algorithm that corrects for the color balance under the different lighting sources (Color temperature). Digital cameras have great difficulty with auto white balance (AWB) — and can create slightly off blue, orange, or even green color casts. Improved auto white balance solutions can help to avoid these color casts, thereby improving the video performance under a wider range of lighting conditions. Color tone (white balance) must be tuned to ensure accurate image reproduction.

CAMERA ENHANCEMENT

Resolution

The amount of detail that the camera can capture is called the resolution, measured in pixels. The more pixels a camera has, the more detail it can capture, and the larger pictures can be without becoming blurry or “grainy.“ Camera sensor resolution should be sufficient to capture enough detail for the target application to avoid such “graininess”.

It is important to note, that video conferencing apps like Zoom or Teams, typically default to 360p (SD), with a manual option to select 720p (HD). Enterprise versions of apps can support up to 1080p (FHD), with meeting room solutions scaling higher. In the vast amount of cases where you have thumbnail sized videos (say when a user is sharing screen, or multiple users in gallery view), the video from a high quality 1Mp (HD) or 8Mp (4K) camera will look very similar due the application streaming resolution and limited screen resolution/pixel count in the space of the thumbnail image. On an FHD screen, the streaming image would have to exceed 50% of total screen area before any pixel limitation in video resolution could occur due to an HD webcam. Incremental system loading of high-resolution video is still to-be-determined.

Tablets, Detachables and phones target more diverse usage models and environments than laptops. Digital zoom and image stabilization (for handheld use) both use a subset of the larger sensor to deliver a lower resolution image at higher quality. For example, Dell’s Latitude 7320 Detachable has a front facing camera with 5MP resolution which helps with stabilization when holding, however 5MP still only provides 1080p video streaming. Selfies benefit from a much larger field of view, to capture both the user and the surroundings.

IR Cameras

IR cameras are simply cameras that capture infrared images, providing secure biometric access and enabling Windows Hello. Windows Hello allows for facial recognition to log-in versus traditional password entry. To be able to use Windows Hello, users must have a device with an IR Camera.

Express Sign-in

Part of Dell Optimizer, ExpressSign-in allows for quicker log-in and works well with Windows Hello. The benefit of ExpressSign-in is that it can detect a user’s presence and wake without moving the touchpad or screen. It can also sense when you walk away and lock the device. ExpressSign-in uses the proximity sensor on select devices in order to do this (which is available as standard on Latitude 9000 and optional on Latitude 7000, 5000 Series). ExpressSign-in can also use the camera for camera-based detection using Intel® Visual Sensing technology. Camera-based detection is not enabled by default; the experience defaults to the proximity sensor and users will be reminded by a banner at the top of the user interface to enable this setting under ‘Special Use Cases’ for enhanced accuracy. Today, camera-based detection is only available on Latitude 9420.

When the device is plugged in to a battery source and user is present/engaged, Dell Optimizer prevents the operating system from locking the PC, even if the user is not physically interacting with the device. For example, user may be reading a long document on the screen. There is also is “Snooze” function that temporarily disables the walk-away lock feature. This is great for when the user wants to keep their device active, even if they are not actively engaged. A good example of this is when the user is in a meeting room and steps away to write on the whiteboard.

CAMERA ENHANCEMENT

Camera Shutters

Many users enjoy peace of mind knowing their built-in webcams can be covered. Some will place tape or stickers to cover them. At Dell, we have added camera shutters to almost all Latitude laptops. You can easily slide the camera shutter over your camera to block out any potential threats. We have also introduced SafeShutter this year which is a shutter that intelligently opens and closes based on your video apps. We asked ourselves, can there be a balance between the convenience of seamlessly joining video calls with the privacy and the safety of knowing the camera is secure?

Enter SafeShutter, available on the new Latitude 9420 and 9520 devices. It’s the industry’s first automatic security webcam that knows when to open or close by syncing to your video conferencing applications (if you give it permission), so you can work securely and confidently from anywhere.¹ Though it connects to your video conferencing software, it lets you take control of your privacy with camera disable (F9) and mic mute (F4) keys to override software settings. Aimed against malicious surveillance and hacking, the keys provide extra assurance at the hardware level and offer additional security. The team designed a new security-hardened, hardware-controlled circuit that is tied to the F4 and F9 keys. When you press a key, you can instantly turn the camera on or off, or hardware mute or unmute your mic. No fumbling and losing precious time to turn off your video through the conferencing software should the unexpected occur. A simple touch of the key will turn it off.

Intel® IPU 6

Intel® IPU (Image Processing Unit) 6 camera technology is Intel’s latest ISP (Image Signal Processor). It’s a powerful engine integrated in the CPU that delivers pleasing image quality by making hazy images better and preserving details. IPU 6 delivers great quality even in brightly lit backgrounds as well as making images excellent in dark environments while recovering color information from IR containment. Today, Dell provides Intel® IPU 6 on Latitude 9420 as well as Latitude 7320 Detachable. Below is a screenshot from Latitude 7320 Detachable from the 8MP rear-facing camera. You can see at the top of the screen the ability on camera mode to create a timer, adjust white balance, choose manual or auto focus, adjust ISO, shutter speed, brightness and HDR (High Dynamic Range, which is not pictured but to the left). Those adjustment features are unique to those devices as all other Latitudes only offer timer or brightness adjustment.

Dell’s cameras remain a priority

With laptops, each one must make trade-offs between camera quality and overall camera size. This trade-off can be particularly challenging for InfinityEdge bezel laptops such as Latitude 9000 and XPS. To gain more screen real estate and less thick borders, Dell’s ultra-premium laptops offer these very narrow InfinityEdge bezels, however they do require miniaturized camera modules (which were not available in higher resolution). Going forward, Dell is looking to improve cameras as the laptop webcam industry innovates.

In sum, Dell offers a wide range of camera options from HD, FHD, to 5MP along with Temporal Noise Reduction (TNR) for clearer video quality. Dell also partnered with Intel® to add their IPU 6 camera technology on Latitude 9420 and 7320 Detachable which for better video enhancements. We plan to keep improving the video collaboration experience in the future and continue to provide some of the best webcams in business laptops.

This photo was taken during a cloudy day with very little to no light to best show the camera quality

¹ Based on Dell internal analysis of publicly available data performed in November 2020. SafeShutter is available on Latitude 9000 series only.

CAMERA ENHANCEMENT

Here is a look at some Dell Latitude cameras compared to top competitors2:

Latitude 9420 (HD, IPU 6)

Latitude 7320 Detachable (5MP)

Competitor (HD)

Competitor (5MP)

Latitude 9420 offers Intel® IPU6  camera technology which is Intel’s latest ISP (Image Signal Processor). Along with Auto White Balance and Dell’s Temporal Noise Reduction (TNR), this HD camera provides enhanced video quality. You can see here with IPU6 camera it was able to brighten this user’s face.

Latitude 7320 Detachable has a 5MP (FHD) front facing camera, an 8MP rear-facing camera along with Intel® IPU6 camera technology which is Intel’s latest ISP (Image Signal Processor). The higher resolution camera provides more detail and more accurate skin tones.

This competitor system is the same form factor, screen size and price range as Latitude 9420. On this system’s webcam you can see the shirt looks a bit blurry and the picture looks washed out.

This competitor system is also a popular tablet/detachable. This system’s webcam also includes a 5MP (FHD) front facing camera as well as an 8MP rear-facing camera.

2 All photos are screen shots and taken in similar lighting conditions on video mode in the native Windows camera app. Based on Dell internal analysis performed in June 2021, actual results may vary depending on video/photo application used, system configurations and environment.

CAMERA ENHANCEMENT

Latitude 7320 Detachable (5MP)

Latitude 7420 (FHD)

Latitude 7420 (FHD)

Competitor (5MP)

Competitor (HD)

Competitor (HD)

Latitude 7320 Detachable has a 5MP (FHD) front facing camera, an 8MP rear-facing camera along with Intel® IPU6 camera technology which is Intel’s latest ISP (Image Signal Processor). The higher resolution camera provides more detail and more accurate skin tones.

Latitude 7420 offers many FHD camera options (2MP). This FHD option can deliver more detail and more accurate color reproduction than competition.

Latitude 7420 offers many FHD camera options (2MP). This FHD option can deliver more detail and more accurate color reproduction than competition.

This competitor system is a 13” laptop 2-in-1 with a 5MP webcam. You can see there is some noise in the video that can make it seem less clear.

This competitor system is the same form factor, screen size and price band. Most popular business laptops in this price band currently do not offer FHD webcam options.

This competitor system is the same form factor, screen size and price band. Most popular business laptops in this price band currently do not offer FHD webcam options.